n | a(n) |
---|---|
0 | 0 |
1 | 21 |
2 | 168 |
3 | 756 |
4 | 2520 |
5 | 6930 |
6 | 16632 |
7 | 36036 |
8 | 72072 |
9 | 135135 |
10 | 240240 |
11 | 408408 |
12 | 668304 |
13 | 1058148 |
14 | 1627920 |
15 | 2441880 |
16 | 3581424 |
17 | 5148297 |
18 | 7268184 |
19 | 10094700 |
20 | 13813800 |
21 | 18648630 |
22 | 24864840 |
23 | 32776380 |
24 | 42751800 |
25 | 55221075 |
26 | 70682976 |
27 | 89713008 |
28 | 112971936 |
29 | 141214920 |
30 | 175301280 |
[0,21,168,756,2520,6930,16632,36036,72072,135135, 240240,408408,668304,1058148,1627920,2441880, 3581424,5148297,7268184,10094700,13813800, 18648630,24864840,32776380,42751800,55221075, 70682976,89713008,112971936,141214920,175301280] |